Over the long term and geologic time,
volcanic eruptions and related processes have directly and
indirectly benefited mankind. Volcanic materials ultimately
break down and weather to form some of the most
fertile soils on Earth, cultivation of
which has produced abundant food and fostered civilizations.
People use
volcanic products, the internal heat
associated with young volcanic systems has been harnessed to
produce
geothermal energy, and most of the
metallic minerals mined in the world,
such as copper, gold, silver, lead, and zinc, are associated
with magmas found deep within the roots of extinct volcanoe.